diff --git a/tests/workflows/preprocessing.nf.test.snap b/tests/workflows/preprocessing.nf.test.snap
index 3c03a636..0c6aed7c 100644
--- a/tests/workflows/preprocessing.nf.test.snap
+++ b/tests/workflows/preprocessing.nf.test.snap
@@ -3,7 +3,7 @@
         "content": [
             {
                 "align_reports": [
-
+                    
                 ],
                 "crams": [
                     [
@@ -35,19 +35,19 @@
                     ]
                 ],
                 "demultiplex_interop": [
-
+                    
                 ],
                 "demultiplex_logs": [
-
+                    
                 ],
                 "demultiplex_reports": [
-
+                    
                 ],
                 "falco_html": [
-
+                    
                 ],
                 "falco_txt": [
-
+                    
                 ],
                 "fastp_html": [
                     [
@@ -118,7 +118,7 @@
                     ]
                 ],
                 "fastq": [
-
+                    
                 ],
                 "md5sums": [
                     [
@@ -233,7 +233,7 @@
                     ]
                 ],
                 "mosdepth_per_base_d4": [
-
+                    
                 ],
                 "mosdepth_quantized_bed": [
                     [
@@ -292,13 +292,13 @@
                     ]
                 ],
                 "mosdepth_regions": [
-
+                    
                 ],
                 "mosdepth_regions_bed": [
-
+                    
                 ],
                 "mosdepth_regions_csi": [
-
+                    
                 ],
                 "mosdepth_summary": [
                     [
@@ -329,10 +329,10 @@
                     ]
                 ],
                 "mosdepth_thresholds_bed": [
-
+                    
                 ],
                 "mosdepth_thresholds_csi": [
-
+                    
                 ],
                 "multiqc_data": [
                     [
@@ -343,7 +343,7 @@
                     ]
                 ],
                 "multiqc_plots": [
-
+                    
                 ],
                 "multiqc_report": [
                     [
@@ -355,21 +355,21 @@
                 ],
                 "multiqcsav_data": [
                     [
-
+                        
                     ]
                 ],
                 "multiqcsav_plots": [
                     [
-
+                        
                     ]
                 ],
                 "multiqcsav_report": [
                     [
-
+                        
                     ]
                 ],
                 "panelcoverage": [
-
+                    
                 ],
                 "riker_alignment_metrics": [
                     [
@@ -428,13 +428,13 @@
                     ]
                 ],
                 "riker_error_indel": [
-
+                    
                 ],
                 "riker_error_mismatch": [
-
+                    
                 ],
                 "riker_error_overlap": [
-
+                    
                 ],
                 "riker_gcbias_detail": [
                     [
@@ -493,13 +493,13 @@
                     ]
                 ],
                 "riker_hybcap_metrics": [
-
+                    
                 ],
                 "riker_hybcap_per_base": [
-
+                    
                 ],
                 "riker_hybcap_per_target": [
-
+                    
                 ],
                 "riker_isize_histogram": [
                     [
@@ -715,10 +715,10 @@
                     ]
                 ],
                 "rna_junctions": [
-
+                    
                 ],
                 "rna_splice_junctions": [
-
+                    
                 ],
                 "samtools_coverage": [
                     [
@@ -882,18 +882,18 @@
                                 "library": "test",
                                 "tag": "WES",
                                 "purpose": [
-
+                                    
                                 ],
                                 "organism": "Homo sapiens",
                                 "genome": "GRCh38",
                                 "vivar_project": [
-
+                                    
                                 ],
                                 "binsize": [
-
+                                    
                                 ],
                                 "panels": [
-
+                                    
                                 ],
                                 "aligner": "bwamem",
                                 "markdup": "bamsormadup",
@@ -933,7 +933,7 @@
         "content": [
             {
                 "align_reports": [
-
+                    
                 ],
                 "crams": [
                     [
@@ -966,19 +966,19 @@
                     ]
                 ],
                 "demultiplex_interop": [
-
+                    
                 ],
                 "demultiplex_logs": [
-
+                    
                 ],
                 "demultiplex_reports": [
-
+                    
                 ],
                 "falco_html": [
-
+                    
                 ],
                 "falco_txt": [
-
+                    
                 ],
                 "fastp_html": [
                     [
@@ -1051,7 +1051,7 @@
                     ]
                 ],
                 "fastq": [
-
+                    
                 ],
                 "md5sums": [
                     [
@@ -1170,7 +1170,7 @@
                     ]
                 ],
                 "mosdepth_per_base_d4": [
-
+                    
                 ],
                 "mosdepth_quantized_bed": [
                     [
@@ -1347,10 +1347,10 @@
                     ]
                 ],
                 "mosdepth_thresholds_bed": [
-
+                    
                 ],
                 "mosdepth_thresholds_csi": [
-
+                    
                 ],
                 "multiqc_data": [
                     [
@@ -1361,7 +1361,7 @@
                     ]
                 ],
                 "multiqc_plots": [
-
+                    
                 ],
                 "multiqc_report": [
                     [
@@ -1373,66 +1373,66 @@
                 ],
                 "multiqcsav_data": [
                     [
-
+                        
                     ]
                 ],
                 "multiqcsav_plots": [
                     [
-
+                        
                     ]
                 ],
                 "multiqcsav_report": [
                     [
-
+                        
                     ]
                 ],
                 "panelcoverage": [
-
+                    
                 ],
                 "riker_alignment_metrics": [
-
+                    
                 ],
                 "riker_base_dist": [
-
+                    
                 ],
                 "riker_error_indel": [
-
+                    
                 ],
                 "riker_error_mismatch": [
-
+                    
                 ],
                 "riker_error_overlap": [
-
+                    
                 ],
                 "riker_gcbias_detail": [
-
+                    
                 ],
                 "riker_gcbias_summary": [
-
+                    
                 ],
                 "riker_hybcap_metrics": [
-
+                    
                 ],
                 "riker_hybcap_per_base": [
-
+                    
                 ],
                 "riker_hybcap_per_target": [
-
+                    
                 ],
                 "riker_isize_histogram": [
-
+                    
                 ],
                 "riker_isize_metrics": [
-
+                    
                 ],
                 "riker_mean_qual": [
-
+                    
                 ],
                 "riker_pdf": [
-
+                    
                 ],
                 "riker_qual_dist": [
-
+                    
                 ],
                 "riker_rna_biotype": [
                     
@@ -1447,19 +1447,19 @@
                     
                 ],
                 "riker_wgs_coverage": [
-
+                    
                 ],
                 "riker_wgs_metrics": [
-
+                    
                 ],
                 "rna_junctions": [
-
+                    
                 ],
                 "rna_splice_junctions": [
-
+                    
                 ],
                 "samtools_coverage": [
-
+                    
                 ],
                 "samtools_flagstat": [
                     [
@@ -1520,7 +1520,7 @@
                     ]
                 ],
                 "samtools_stats": [
-
+                    
                 ],
                 "sormadup_metrics": [
                     [
@@ -1563,7 +1563,7 @@
         "content": [
             {
                 "align_reports": [
-
+                    
                 ],
                 "crams": [
                     [
@@ -1596,19 +1596,19 @@
                     ]
                 ],
                 "demultiplex_interop": [
-
+                    
                 ],
                 "demultiplex_logs": [
-
+                    
                 ],
                 "demultiplex_reports": [
-
+                    
                 ],
                 "falco_html": [
-
+                    
                 ],
                 "falco_txt": [
-
+                    
                 ],
                 "fastp_html": [
                     [
@@ -1681,7 +1681,7 @@
                     ]
                 ],
                 "fastq": [
-
+                    
                 ],
                 "md5sums": [
                     [
@@ -1800,7 +1800,7 @@
                     ]
                 ],
                 "mosdepth_per_base_d4": [
-
+                    
                 ],
                 "mosdepth_quantized_bed": [
                     [
@@ -1977,10 +1977,10 @@
                     ]
                 ],
                 "mosdepth_thresholds_bed": [
-
+                    
                 ],
                 "mosdepth_thresholds_csi": [
-
+                    
                 ],
                 "multiqc_data": [
                     [
@@ -1991,7 +1991,7 @@
                     ]
                 ],
                 "multiqc_plots": [
-
+                    
                 ],
                 "multiqc_report": [
                     [
@@ -2003,21 +2003,21 @@
                 ],
                 "multiqcsav_data": [
                     [
-
+                        
                     ]
                 ],
                 "multiqcsav_plots": [
                     [
-
+                        
                     ]
                 ],
                 "multiqcsav_report": [
                     [
-
+                        
                     ]
                 ],
                 "panelcoverage": [
-
+                    
                 ],
                 "riker_alignment_metrics": [
                     [
@@ -2078,13 +2078,13 @@
                     ]
                 ],
                 "riker_error_indel": [
-
+                    
                 ],
                 "riker_error_mismatch": [
-
+                    
                 ],
                 "riker_error_overlap": [
-
+                    
                 ],
                 "riker_gcbias_detail": [
                     [
@@ -2170,14 +2170,14 @@
                                 "id": "sample1"
                             }
                         },
-                        "sample1.hybcap-metrics.txt:md5,0e5cf0bfd2f1142f56462ec7cf4c990c"
+                        "sample1.hybcap-metrics.txt:md5,7cae4a6cf3b7b4bf0958553c1c89ed62"
                     ]
                 ],
                 "riker_hybcap_per_base": [
-
+                    
                 ],
                 "riker_hybcap_per_target": [
-
+                    
                 ],
                 "riker_isize_histogram": [
                     [
@@ -2342,16 +2342,16 @@
                     
                 ],
                 "riker_wgs_coverage": [
-
+                    
                 ],
                 "riker_wgs_metrics": [
-
+                    
                 ],
                 "rna_junctions": [
-
+                    
                 ],
                 "rna_splice_junctions": [
-
+                    
                 ],
                 "samtools_coverage": [
                     [
@@ -2500,10 +2500,10 @@
                 ]
             }
         ],
-        "timestamp": "2026-07-07T11:20:32.551532",
+        "timestamp": "2026-07-09T14:50:22.070749",
         "meta": {
             "nf-test": "0.9.5",
             "nextflow": "26.04.4"
         }
     }
-}
+}
\ No newline at end of file
diff --git a/workflows/preprocessing.nf b/workflows/preprocessing.nf
index e051f8b3..3fdc7bd2 100644
--- a/workflows/preprocessing.nf
+++ b/workflows/preprocessing.nf
@@ -184,7 +184,7 @@ workflow PREPROCESSING {
             }
             return [meta, reads]
         }
-        .map { meta, reads -> [meta.samplename, [meta, reads]] }
+        .map { meta, reads -> [[meta.samplename, meta.library], [meta, reads]] }
         .groupTuple()
         .map { _samplename, meta_fastq -> [meta_fastq, meta_fastq.size()] }
         .transpose()